| 摘要 |
Production of synthetic vinyl resins having pronounced resistance to color deterioration, while also manifesting high impact strength and transparency, utilizing a butadiene graft polymer formed by the sequential addition to a polymer or copolymer of butadiene of from 80 to 30 parts of monomers for each 100 parts of total resin content, said monomers consisting of from 5 to 80 percent vinyl aromatic compound, from 5 to 50 percent of methyl methacrylate, and from 5 to 60 percent of acrylonitrile, the process being characterized in that at least 80 percent of the butadiene particles at the start are less than 0.1 mu in diameter and are dispersed in an aqueous emulsion which contains from 0.5 to 10.0 parts of a formaldehyde sulfoxylic salt, and catalytically effective amounts up to three parts of peroxide, for each 100 parts of resinous constituents used, said particle size being maintained at least until polymerization of the monomeric material has been effectively begun, said butadiene graft polymer being independently useful but also being capable of blending with a resin of the vinyl chloride type to produce a final resin of greatly enhanced properties.
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